ITU-T Z.321 PDF

Scope of the Section

This Section deals with man-machine interfaces that take advantage of the input and output facilities usually available on visual display terminals (VDTs). The procedures described are not necessarily confined to this type of terminal; they can also be applied to printer-oriented terminals, such as teletypewriters, within the limits imposed by the facilities available at those terminals, e.g., information entry through menu selection.

By maintaining consistency with Recommendations Z.311-Z.317, these Recommendations facilitate a transition from a man-machine interface using basic syntax and dialogue procedures as described in Section 1 to one based on VDTs

Diagrams and examples are used to clarify and illustrate the concepts explained in the text. The diagrams do not include exceptional cases and do not specify all possibilities available with the extended MML; those not shown diagrammatically, but which are allowed in the text, are subjects for further study and are not excluded from the extended MML. Similarly, the examples shown are not intended to imply a particular system implementation.

The Recommendations cover aspects of VDTs that users see and use, e.g., data entry, data display, interactive control, user guidance, etc. Specific terminal characteristics are avoided wherever possible.